This F31 application proposes research training for Jessica Rearden, a fourth year doctoral student at the University of Pennsylvania. The long-term goal of this application is to prepare the applicant to become an independent investigator who will build a funded program of research at a research-intensive academic institution. The focus of her work is to identify and eliminate disparities in cancer clinical trial (CCT) participation for underrepresented groups. The first step in her training is to complete course work and a dissertation under the supervision of her mentoring team. To eliminate disparities in participation and increase the generalizability of trial findings, all cancer patients should have the opportunity to participate in CCTs regardless of ancestry, age, sex, or socio-economic status. [Opportunity for participation is defined as an offer for screening and/or enrollment in a CCT from a healthcare provider or researcher.] Approximately 3-5% of adult new cancer patients participate in CCTs, and racial and ethnic minorities, older adults, and the economicaly disadvantaged are significantly under-represented. Contrary to popular assumptions, evidence suggests that underrepresented groups are just as willing to participate in CCTs as well-represented groups. [The applicant proposes a cross-sectional design, including a patient questionnaire and retrospective medical record review, to study opportunity to participate n CCTs (opportunity / no opportunity), while stratifying by eligibility status (eligible / ineligible for enrolling CCTs). Participants will be stratified as follows: patients wit opportunity to participate who are eligible (OE), patients with opportunity to participate who are ineligible (OI), patients without opportunity to participate who are eligible (NE), and patients without opportunity who are ineligible (NI). The study sample will consist of new cancer patients seen by a medical oncologist at an NCI- designated Comprehensive Cancer Center during a 6-month period. The sampling plan will include two Non- Hispanic White participants for every Black or Hispanic participant, matched on cancer type (leukemia, breast, lung, kidney) and age (+/- 5 years).] The short-term goals of this application include 1) comparing differences in socio-demographic variables (age, [race/ethnicity], sex, primary spoken language, insurance status) between the following four groups: Opportunity-Eligible [OE] Group, Opportunity-Ineligible [OI] Group, No opportunity-Eligible [NE] Group and No opportunity-Ineligible [NI] Group~ 2) examining the relationship between patient socio-demographic variables and eligibility status (eligible / ineligible), and 2a) examining the relationship between socio-demographic variables and specific reasons for exclusion for those variables demonstrating significant associations with eligibility status. A third exploratory aim will be to examine the independent socio-demographic predictors of opportunity among patients who are eligible. This application reflects the National Instituteof Nursing Research (NINR) strategic goals of promoting health for patients with chronic illness and eliminating health disparities.